1. Field of the Invention
The present invention relates to memory module sockets and improving signal quality related to memory module sockets.
2. Background of the Related Art
Memory module sockets are used in a computer system to provide communication between memory modules, such as either a single in-line memory module (SIMM) or a dual in-line memory module (DIMM), and a processor package mounted on a printed circuit board. The memory module sockets include pins for physically attaching the sockets to a circuit board. The pins fit through holes in the circuit board and, typically, the pins are either soldered or press-fitted to the board to form a physical connection between the memory module socket and the printed circuit board. The physical connection allows electrical signals to pass between the memory module socket and the processor package on the printed circuit board. When a memory module is received within the memory module socket, the processor package is able to communicate with the module through the socket.
Recent increases in processor performance require higher frequency electrical signals and lower voltages to pass within a memory bus to the memory modules. With lower voltages, electronic “noise” caused by stubs on the printed circuit board has a greater effect on the signal quality. A stub is a trace, pin or a portion of a trace or pin on a printed circuit board that does not connect to another element. For example, a stub can occur in an empty memory module socket and cause noise that can substantially affect the integrity of the communications with memory modules received in adjacent memory module sockets. As a result, signal quality for a populated memory module socket connected in series or parallel with an empty memory module socket may be reduced.